Brisbane's Catholic Justice and Peace Commission is encouraging Catholics to take action to oppose the execution of Australian man, Van Tuong Nguyen, which is scheduled to occur in Singapore on 2 December.

It has also asked Catholics to understand that opposition to the death penalty is a part of the Christian witness to the Gospel of life.

The Commission's Executive Officer, Peter Arndt, said that it is important for Catholics to defend the sanctity of human life unconditionally.

"We appreciate Prime Minister Howard's intense opposition to the execution of Van Nguyen and commend the Australian Government's efforts to appeal for clemency on behalf of Mr Nguyen," Mr Arndt said.

"We are very grateful to Mr Howard for his personal commitment and intervention in this matter," he said. "However, as Christians, we should understand that it is important to be defending Mr Nguyen's right to life without condition," he said.

"When we appeal for his life, we do so because all human life is sacred and not simply because there are some extenuating circumstances in his particular case which deserve clemency from the Singapore Government," he said.

"Whatever the circumstances, we should seek to promote life as a right and not as a privilege," he said.

"Van Nguyen made a bad choice to traffic in drugs which have serious consequences for many other people and justice demands that he face serious consequences for his serious wrongdoing," he said.

"But justice also demands that his life be protected and defended as a basic human right," he said.

The Commission is asking that Catholics pray constantly for Van Tuong Nguyen and for his mother and his family over the course of the next fortnight.

"In addition to the powerful action of prayer, we also hope that Catholics would add their voices to the Prime Minister's in appealing to the Singapore Government for Van Nguyen's life.